1. Field of the Invention
The invention relates to the lubrication of vehicle axle carrier pinion bearings and, more particularly, to a structure for controlling the flow of lubricant through the pinion bearings in a vehicle axle carrier.
2. Summary of Related Art
In operation, axle carrier pinion bearings are generally lubricated with oil which is circulated from a sump or reservoir by a drive gear through a passage located between the inboard and outboard pinion bearings. Oil entering the passage between the pinion bearings is typically drawn into and through both the inboard and outboard pinion bearings. The oil flowing through the outboard pinion bearing is directed back into the passage between the pinion bearings. From this passage, some of the oil is drawn into the inboard pinion bearing for return to the sump, while the remainder of the oil is recirculated directly through the outboard pinion bearing.
As it is circulated through the bearings the temperature of the oil tends to increase, and the recirculation of high temperature oil directly through the outboard pinion bearing disadvantageously causes a significant temperature difference between the oil in the outboard pinion bearing and the oil in the sump. Additionally, the oil may drain from the outboard pinion bearing if the associated vehicle is parked on a sufficiently steep incline, resulting in an initial period of operation without lubrication upon startup.